This invention relates to a flashback or patency check device to indicate proper venipuncture in conjunction with a blood or parenteral administration set. More particularly, this invention relates to a flashback component which is formed as an intregral unit and will not become detached from the set during normal usage.
Flashback indicators of the type concerned with in this invention are described in the Gewecke U.S. Pat. No. 2,868,200. As explained therein, one of the functions of a flashback indicator is to show that the hypodermic needle or catheter through which the fluid enters the body has indeed punctured a vein. The problem with the unit described in the Gewecke patent is that it is difficult to obtain a seal between the tubing which is typically polyvinyl choride and the flashback indicator which is typically latex so that it can withstand the pressures exerted in the set when a hypodermic syringe is utilized to administer additional medication. When these materials are employed, the only bond is friction. In many instances where such a syringe has been employed, sets utilizing these components have been known to break apart or leak at the junction of the tubing and the flashback indicator. Where the flashback indicators have been blown off the sets, much distress has been caused to the patient as well as causing much concern to the administrator of the I.V. fluids as the patient is in many instances already under an emergency condition.
U.S. Pat. No. 3,674,404 issued to Burlis, et al. describes bubble tubing which is extruded with various external and internal diameters as well as wall thicknesses. The tubing is indicated for use in various types of catheters, drainage and aspiration tubes as well as tubing having tapered end portions for interconnecting various biomedical devices.
Nowhere in the prior art is there provided a flashback or patency check device which can be formed as an integral part of a parenteral or blood I.V. administration set so that entry into a vein is immediately indicated yet additional medication can be administered quickly and under rapid and relatively high pressure conditions without the flashback indicator being disconnected from the set.
It is an advantage of the present invention to provide a flashback or patency check device which can be formed integrally with an I.V. administration set and which will not become detached during normal usage. Other advantages are a flashback indicator which is economical to manufacture and assemble; can be constructed in various configurations and sizes to fit the various capacities of I.V. administration sets; can be formed as a portion of the flexible tubing in an I.V. administration set thereby reducing the cost thereof.